From the writers of Superbad, here's another excitedly silly stoner comedy that keeps us laughing from start to finish. It's pretty pointless, really, but the characters are so engaging that we can't help but fall for them.

Dale (Rogen) is a 25-year-old who enjoys life's simpler pleasures--mainly smoking pot. He works as a process server and is terrified about meeting the parents (Begley and Dunn) of his 18-year-old girlfriend (Heard). When he witnesses a murder committed by a cop (Perez) and a drug kingpin (Cole), he goes on the run with his dealer Saul (Franco), who's possibly his best friend. But the baddies' goons (Corrigan and Robinson) have traced their primo Pineapple Express weed through the supplier (McBride) and are coming after them.

The film opens with a ridiculous black and white sequence showing the 1937 US military experimenting with the effects of reefer, as demonstrated by a giggling private (Hader) and a no-fun officer (Remar) who declares marijuana "illegal!" Cut to Rogen's buzzed-out life and the quickly escalating mayhem of the plot. Nothing arthouse director Green has done prepares us for his surprisingly light-handed direction here, keeping the pace brisk, the characters grounded and the comedy hilarious from start to finish.

Meanwhile, the gifted cast members never overplay their characters, no matter how preposterous they become. And as absurd as they are, they're also solidly believable. And very funny too, with dialog that's bursting with terrific one-liners. Rogen and Franco anchor the wackiness with effortlessly scruffy performances as deeply likeable losers who, despite their paranoia, have no idea how much trouble they're in or how lucky they are to survive even one encounter with these nasty thugs.

Which perhaps is the film's one uneven touch: the violence is genuinely grisly, with death and destruction on an almost Michael Bay scale. That said, most of the action scenes are sublimely hysterical, including a madcap car chase and an out-of-control ninja invasion. And while a few gags don't work (such as a gay innuendo-filled escape), the film is packed with moments of mercifully underplayed emotion and genius improv. Which almost makes up for the "drugs don't hurt you, they just make you stupid" message.